Results were reported from the following four Mars-3 experiments: (1) infrared brightness temperature measurements of Mars surface in 8-40 micrometers range; 2) Mars surface-relief determination from intensity variation of CO2 quanity in micrometers absorption band; 3) H2O content in atmospheric measurement from intensity of 1.38 micrometers absorption band; 4) planet photometry in 5 narrow spectral bands within 3700-7000 A range. Thermal inertia constant of Martian ground was about 0.006 cal/sq cm sec to -1/2 power/deg. This is typical of dry dust at low pressure. Temperature difference between dark (warmer) and light surface areas was approximately 10-15 C. In polar cap areas, temperatures close to CO2 condensation temperature were recorded. A dust storm created an antigreenhouse effect. Altitudes along ground observation tracks varied from -2 to 5 km. Cloud altitude during the dust storm was of the order of 10 km. Water content was very low - a few micrometers of precipitable water from Dec. to Feb.